Two female documentary filmmakers, kidnapped and held by an Al-Qaeda-aligned group in the Philippines nearly nine months ago, escaped from their captors and were recovered by local authorities on Thursday.

The women, sisters Nadjoua and Linda Bansil, were abducted by the Islamic extremist group Abu Sayyaf Group (ASG) last June while filming a documentary about impoverished Islamic coffee growers in the Philippines' restive south. The sisters are residents of Zamboanga City in the Philippines.

The directors were recovered on the island of Jolo during a military search for them, according to a statement from a local marine brigade.

"The safe recovery was made possible through the intensified conduct of law enforcement operations," the statement said. The report added that due to military pressure, the captors loosened their grip on the two women and they were able to escape. Further details of the rescue weren't provided.

Nadjoua Bansil, also a human rights advocate, has produced several documentaries (Bohe: Sons of the Waves, 2012) exploring the marginalized sectors of Philippine society. Linda Bansil was also a writer for Amnesty International in the Philippines.

The Abu Sayyaf group is designated by the U.S. government as a terrorist organization. It is believed that Osama bin Laden helped found and finance the organization in the 1990s as a Philippine-based Al-Qaeda-linked cell. The group has been traced to numerous deadly terrorist attacks in the Philippines. Several other hostages remain in ASG captivity, according to the Agence France-Presse, including two European bird watchers.